1. Field of the Invention
The present invention relates to an adaptor for electronic element sticks employed in automatic assembling of printed circuit boards.
2. Description of the Prior Art
An automatic inserter for assembling printed circuit boards has been known in which constituent electronic elements such as an IC chip, semiconductor, resistor and capacitor are delivered and installed in specified positions on the boards in an automatic manner. These various elements are supplied one by one to the inserter through respective dispensers. Each dispenser employs an elongated stick or tube which contains a number of electronic elements in a row.
In mass-scale production, a number of stacked sticks are provided for each dispenser. The inner ends of the stacked sticks are received between a pair of opposed side walls of a guide frame in the dispenser, and the elements loaded in the lowermost stick adjacent to an inlet of the dispenser are first unloaded. When the all the elements have been unloaded from the lowermost stick, this empty stick is ejected from the guide frame and the ensuing stick is guided downwardly in the guide frame to occupy the lowermost unloading position.
One serious problem concerned with the electric element sticks of the prior art is that the commercial sticks containing the respective elements differ in width from one another according to the makers. So long as the stick has a width slightly smaller than the fixed spacing between the side walls of the guide frame of the dispenser, the stick can be smoothly guided downwardly in the guide frame by gravity, with its attitude being kept proper.
However, in a case where the required electronic elements are loaded in a stick having too small a width and such a narrow-sized stick must be used, there has been an inconvenient tendency for the stick to tilt about its longitudinal axis within the guide frame of the dispenser. As the stacked sticks tilt randomly, they jam in the guide frame. Even if one of the sticks could reach the lowermost position, this stick might fail to be set in alignment with the inlet aperture of the dispenser.